This invention is in the field of sewing machines; more particularly, this invention is concerned with means for retaining a bed slide in the frame of a sewing machine molded of a synthetic resin material.
In the prior art sewing machines, the preferred material has been metal such as cast iron or, more recently, aluminum for its lightness. When it becomes necessary to retain parts or accessories in position in the frame of such a sewing machine it is relatively easy to drill and tap a hole therein and provide for attachment by means of a machine screw.
However, in an effort to find more acceptable lower cost and lighter weight materials, many appliances are being fabricated utilizing synthetic resin materials. The use of the synthetic materials has required the development of new techniques for assembling components to these materials. For example, metal inserts can be molded in place, which inserts may carry internal or external threads for attachment purposes. However, in certain situations, these techniques are not readily applied and further efforts may be required to devise ways of retaining components.
Specifically, heretofore sewing machine bed plates could be slidably retained by cutting a dovetail in a sewing machine bed fabricated of a metallic material and sliding in a bed slide having surfaces correspondingly dovetailed. However, one of the advantages accruing to the use of a synthetic plastic material lies in its use in an as molded state without recourse to machining operations. Also, the synthetic materials are not as amenable to machining as metallic materials.
What is required is some means for retaining a bed side slidably in the bed of a sewing machine having a frame made of a synthetic resin material so that the full advantages of this material may be obtained.